I’ve check that out LONG ago. The reason anything in Hawaii was destroyed was that the street lights and the phone line that were affected were connected to very long wires and had no overvoltage protection. An EMP would have some effect, but very little. Your little computers may have to be rebooted, but they won’t be destroyed. Your car may choke for a second or even stop running but will restart just fine. Most systems wouldn’t even notice an EMP.
EMP isn’t a weapon in the US arsenal because it has little effect.
It is ridiculous to think we were doing SDI in the 1980’s when all we had to do was cause a cheap and easy EMP instead.